This invention relates to an apparatus for transporting a coiler can between a sliver-producing fiber processing machine, such as a carding machine or a drawing frame and a sliver-consuming fiber processing machine, such as a drawing frame or a spinning machine. The apparatus includes a transport carriage associated with a can-shifting device for loading a can onto or unloading a can from the carriage. The shifting device includes elements for grasping the can and also has linearly displaceable shifting elements for moving the can relative to the carriage.
In a known apparatus, by means of a shifting device mounted on the carriage, the sliver-filled coiler can is moved onto or an empty coiler can is moved off the carriage. A gripper is provided which has two horizontal telescoping cylinders. At one end of the cylinder piston a pressure cylinder is arranged at an angle of 90.degree. which operates in the radial direction of the can and clamps the can against the other pressure cylinder situated diametrically opposite, on the other side of the can. The gripping device has two short, arcuate clamping members which are adapted to the curvature of the outer surface of the coiler can. First the clamping parts are moved in a linear direction tangentially to the coiler can in such a manner that the can will be situated between the clamping members. Between the clamping members and the outer surface of the coiler can only small clearances are present. The clamping parts are short to ensure that the can will fit therebetween upon grasping. The length of stroke of the pressure cylinder situated transversely to a horizontal telescoping cylinder is also short. Thereafter the coiler can is, as the pressure cylinder moves radially in the direction of the can, clamped firmly by the clamping components in a frictional manner.
The above-outlined prior art apparatus has several disadvantages:
The grasping of the coiler can requires an accurate movement of the carriage to the location (can emplacement) where can shifting occurs because the coiler can has to be positioned with small lateral clearances in the intermediate space between the facing clamping components (x-direction). Further, the telescoping cylinders with the clamping components have to be positioned accurately relative to the coiler can (y-direction), so that the short clamping components may securely grasp the outer can surface. Such a precise positioning of the clamping components in both the longitudinal and the transverse direction requires substantial technical and constructional outlay and furthermore may lead to operational disturbances.